The Campos Basin is one of 12 coastal sedimentary basins of Brazil. It spans both onshore and offshore parts of the South Atlantic with the onshore part located near Rio de Janeiro. The basin originated in Neocomian stage of the Cretaceous period 145–130 million years ago during the breakup of Gondwana. It has a total area of about , with the onshore portion small at only .]]

thumb|right|250px|Schematic diagram of the formation of a passive margin on a rift basin

The South Atlantic margin developed on Archean stable cratons consisting of hard and resistant rocks and partly on the Neoproterozoic mobile belts composed of less resistant metamorphic rocks. The Precambrian basement of the Santos Basin is exposed as the Araçuaí Belt along the Brazilian coast, most notably in the inselbergs of Rio de Janeiro, of which Sugarloaf Mountain is the most iconic. The ancient rocks consist of a Neoproterozoic to Cambrian high-grade metamorphic core of granites and gneisses, formed during the collision of Gondwana in the Pan-African-Brasiliano orogeny. Basalts similar to the Paraná and Etendeka traps, exposed to the west in the Paraná Basin, have been found underlying the Santos Basin. The Tristan da Cunha hotspot, known as the Tristan hotspot, is considered the driver behind the formation of these flood basalts.

During the Early Cretaceous, the former continent Gondwana, as southern part of Pangea, starting to break-up, resulting in a sequence of rift basins bordering the present-day South Atlantic. The Pelotas-Namibia spreading commenced in the Hauterivian, around 133 million years ago and reached the Santos Basin to the north in the Barremian. Seafloor spreading continued northwards to the Campos Basin in the Early Albian, at approximately 112 Ma.

Five tectonic stages have been identified in the Brazilian basins:

  1. Pre-rift stage – Jurassic to Valanginian
  2. Syn-rift stage – Hauterivian to Late Barremian
  3. Sag stage – Late Barremian to Late Aptian
  4. Post-rift stage – Early to Middle Albian
  5. Drift stage – Late Albian to Holocene

Stratigraphy

Oil reservoirs include formations deposited during the Aptian and pre-Aptian continental rift phase, of post-salt Albian-Cenomanian shallow-water marine carbonates and deepwater sandstones, and in turbidites of the open marine drift phase of Late Cretaceous and early Tertiary ages. The first oil production started in 1977 from Enchova Field, at a water depth of . Albacora (1984), Marlim (1985), Albacora-Leste (1986), Marlim Sul (1987), Marlim Leste (1987), Barracuda (1989), Caratinga (1989), Espadarte (1994), Roncador (1996), Jubarte (2002), Cachalote (2002), and Badejo (2008). The largest Marlim field is located in the northeast of the basin, offshore in water depths ranging from .

By 2003, 41 oil and gas fields were discovered, which ranging at distances from from the coast and at water depths varying from . Of these fields, 37 are being developed by Petrobras. By 2003, the oil production from the basin had reached 1.21 million barrels per day. The production comes from a variety of reservoirs including siliciclastic turbidites, fractured basalts, coquinas, calcarenites (limestones). The total cumulative production from the Campos Basin by 2003 was 3.9 billion barrels of oil with remaining reserves of 8.5 billion barrels.

In February 2010, a new 65 million barrel discovery was made by Petrobras near the Barracuda oil field.

In 2020, the Enchova, Enchova Oeste, Marimbá, Piraúna, Bicudo, Bonito, Pampo, Trilha, Linguado, and Badejo concessions were sold by Petrobras to Trident Energy. These concessions are located in the shallow part of the Campos Basin, offshore Rio de Janeiro state.

See also

  • Angola Basin
  • Pelotas Basin
  • Santos Basin

References

Bibliography and further reading

Brazil general

Campos Basin geology

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Campos Basin exploration

  • Real Time Ship Traffic in the Campos Basin